Virtual reality environments can now appear deceptively real. Researchers have discovered that our minds and senses can be easily deceived in the virtual world. When we wear VR glasses and move around in a virtual environment, we feel touches that are not real. Scientists call this phenomenon the phantom touch illusion.
The use of virtual reality (VR) technologies is widespread in gaming and entertainment. In these virtual worlds, people sometimes feel like they are touching things when in fact they are just encountering virtual objects. A research group led by Artur Pilacinski from the Ruhr University Hospital in Bochum examined in more detail under what circumstances this feeling occurs and whether everyone experiences it. To do this, the neuroscientists had 36 test subjects wear virtual reality glasses and experience VR scenarios. In it, the test subjects were asked to touch their avatar's hands with a virtual stick or a laser pointer and report whether they felt anything.
Phantom touches trigger tingling sensations
32 of the 36 test subjects actually felt a touch in the corresponding place on their real hands - even though there was no physical contact between the virtual stick and the body. “Most subjects described the phantom touch illusion as a tingling or tingling, electrifying feeling, or as if wind was blowing through their hand,” Pilacinski reports. The test subjects experienced this feeling on the palm as well as on the fingers or the back of the hand. Some even felt the phantom touch on their forearms, which were not visible in virtual reality, as the researchers report. However, the test subjects usually only felt the supposed touch when they used a virtual stick. In the experiments, however, the virtual laser pointer only triggered a feeling of touch in a few people.
“This suggests that our perception and body feeling are not only based on visual aspects, but on a complex combination of many sensory perceptions and the internal image of our own body,” says co-author Marita Metzler from the Ruhr University Bochum. The researchers want to find out in follow-up studies what exactly happens in our body - especially in our nerve cells. These studies must, for example, clarify whether the biological processes during phantom touch correspond to the sensations of real skin touch or are “just” imagination in the brain.
Pilacinski and his colleagues suspect that a reverse biological process could occur during phantom touch, like when we tickle ourselves. In this case, we feel the real touch less intensely because we were expecting it. Our nerves are then stimulated less strongly. Conversely, in the virtual world, the mere expectation of a touch could lead to our nerve cells receiving a touch signal, the researchers suspect.
Possible applications in medicine
The findings could be helpful not only for the entertainment industry, but also for medicine. “The discovery of the phantom touch illusion opens up new possibilities for further research into human perception,” says senior author Christian Klaes from the Ruhr University Bochum. “It could help deepen our understanding of neurological diseases and disorders that affect the perception of one’s own body.”
Source: Artur Pilacinski (Ruhr University Bochum) et al., Scientific Reports, doi: 10.1038/s41598-023-42683-0